A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL−1, then what shall be the molarity of the solution?
10% w/w solution of glucose in water means that 10 g of glucose in present in 100 g of the solution i.e., 10 g of glucose is present in (100 − 10) g = 90 g of water.
Molar mass of glucose (C6H12O6) = 6 × 12 + 12 × 1 + 6 × 16 = 180 g mol−1
Then, number of moles
of glucose
= 0.056 mol
Molality
of solution
=
0.62 m
Number of moles of
water
= 5 mol
Mole
fraction of glucose
And, mole fraction of
water
= 1 − 0.011
= 0.989
If the density of the solution is 1.2 g mL−1, then the volume of the 100 g solution can be given as:
Molarity
of the solution
= 0.67 M